The invention relates generally to means for retaining or bracing cargo in cargo bins and more particularly to means for retaining or bracing cargo in vehicles such as trucks, trailers and railroad cars.
Highway traffic or other highway hazards may require sudden braking, quick turning or other emergency maneuver by the operator of a truck trailer. Such maneuvers may cause an improperly secured cargo load to shift quickly. The high momentum resulting from a heavy load shifting when the vehicle is moving at highway speeds can cause the vehicle to tip over or jackknife. Consequently, it is of crucial importance that the cargo retention means used be very effective in preventing undesired cargo movement. Since truck trailer vehicles require the cargo or load to be securely mounted on the trailer to minimize load shifting and prevent undesired movement of the truck trailer combination, the persons loading such vehicles have to spend considerable amounts of time properly placing the cargo in the trailer and tying it down or otherwise securing it to suitable trailer structural components. Many types of cargo retainers have been used but they have typically been difficult to use or require considerable time, effort and skill to properly set up.
Designers of prior art cargo retainers generally believe that the retention means must be large in order to provide safe and secure retention of the cargo, which is often bulky and heavy, in the cargo bin area of the vehicle. Consequently, many prior art cargo retainers are basically support structures for sidewall panelling or tarpaulin covers. An example of such a prior art retainer is disclosed in U.S. Pat. No. 3,811,724 to Woodward. The Woodward device is specifically designed to be used in flat bed trucks and, in one embodiment, has a two piece, vertically slotted stake which fits within sockets at the periphery of the cargo bed. Sidewall panels are inserted between the Woodward stakes and locked in place by means of T-shaped bars which fit in the stake slots. Another Woodward embodiment connects a removable tarpaulin support bow to a pair of telescoping stakes inserted in the sockets. A primary disadvantage of such prior art devices is that the truck or flat bed trailer must have specially constructed stake pockets to accomodate the stake. This can substantially increase the cost of the vehicle. In addition, the particular stakes and cooperating panel structures are somewhat complex and therefore expensive. Moreover, since the supporting sidewall panels can only be positioned at the periphery of the cargo bed, such devices are greatly limited in the dimensional size of the load they can retain.
Some types of prior art cargo retainers are designed to separate and restrain groups of cargo items in a load. Such prior art cargo retainers are generally very limited in their ability to restrain movement of loads of various dimensional sizes. Consequently, the user must have a range of sizes of such devices in order to restrain loads within a range of dimensional sizes. Thus, truckers using such devices must either have many such devices on hand to accomodate a variety of load sizes or they must purchase new devices whenever they find they have a cargo load of a different size to transport. Therefore, such devices tend to be expensive and not very practical for transporting a variety of different types of cargo. Moreover, many such devices may be required to accomodate vehicles of different sizes or dimensions.
Many prior art cargo retainers utilize tie down straps or bands to provide a variable restraint mechanism. An example of such a prior art retainer is disclosed in U.S. Pat. No. 4,219,229 to Ciocan. The Ciocan device incorporates stanchions fitting into appropriately sized and shaped slots in the cargo bed. Once inserted in the slots, each stanchion has special structures thereon which allow a twisting movement of the stanchion to lock the stanchion in the slot. The slots are placed at selected locations on the cargo bed where it is deemed that they will be adjacent or at least proximal the expected cargo load. Thus, in order to accomodate various loads, such prior art devices must have a specially constructed cargo bed with a large number of strategically located slots. This requirement makes use of such prior art devices expensive. In addition, the thinness and narrow width of such tie down straps and bands makes them subject to stretching and breakage particularly with heavy loads. Such prior art tie down systems are thus not able to restrain heavy loads very well. In an attempt to overcome this disadvantage, many users increase the number and vary the placement of the straps and bands. However, this makes use of such systems more troublesome, labor intensive and time consuming. Therefore, such devices not only may require an inordinate amount of labor to set up but may also be of limited effectiveness in securely retaining many cargo loads in the cargo bin.
Other prior art cargo retaining systems use a chain to tie down a load. However, such systems require suitable anchors for attachment of the chain to the vehicle. The anchors are typically welded at suitable locations on or under the truck trailer support structures. But, the costs of affixing these anchors may make such systems inordinately expensive. Moreover, the anchor requirement makes it difficult to reposition the restraint chains at various desired locations in order to properly secure various cargo loads. In addition, proper tightening of all of the chains to ensure adequate cargo restraint may involve undue physical exertion on the part of the user.
A cargo restrainer is thus needed that can be positioned in various locations, as needed to accomodate various load sizes. A cargo restrainer is also needed that is inexpensive to manufacture and utilize and that can be used in various types and sizes of vehicles without requiring the affixation of special support structures on the vehicle.